Speaker
Description
One of the best ways to understand the spin structure of the proton is through Generalized parton distributions (GPDs) which are in principle accessible in exclusive deeply virtual photon electroproduction processes. However, in order to extract these GPDs, a proper understanding of the phase structure of the cross section is vital. In particular, the phase structure plays a key role in the extraction of GPDs closely related to the proton’s orbital angular momentum. As a step towards understanding this phase structure, we study deeply virtual photon electroproduction from a spin ½ quark target. We provide the general expression for the various contributions to the cross section, namely: the deeply virtual Compton scattering process, the Bethe-Heitler process, and their interference. All of these are described within a helicity amplitude based framework that is relativistically covariant, making it readily applicable to both laboratory and collider kinematic settings. We will discuss calculations of observables (cross sections and spin asymmetries) for the proton and deuterin targets, providing details on the electric charge, quadrupole, magnetic, and axial vector properties.
